#include<bits/stdc++.h>
using namespace std;
const long long mod=998244353;
long long n,m,k;
long long ksm(long long a,long long b,long long mod){
	if(!b) return 1ll;
	long long c=ksm(a,b>>1,mod);
	c=c*c%mod;
	if(b&1) c=c*a%mod;
	return c;
}
int main(){
	freopen("plusminus.in","r",stdin);
	freopen("plusminus.out","w",stdout);
	cin>>n>>m>>k;
	for(long long i=1;i<=k;i++){
		int x,y,z;
		cin>>x>>y>>z;
	}
	if((n+m)%2==1){
		cout<<0<<"\n";
		return 0;
	}
	cout<<ksm(2,n*m-n-m-k+1,mod)<<"\n";
	return 0;
}